Sound Trap in a Superfluid ⚡ экспресс
The study extends earlier findings on quasi-bound states of massless acoustic excitations in an effective acoustic spacetime with circulation. This acoustic black hole captures the phenomenology seen in superfluid experiments. The challenge is that vortex flows on scales larger than the intervortex distance exhibit solid-body rotation at a constant angular velocity Ω, complicating the analysis. In this work, the corresponding term is added to the model, and a spectral analysis is performed using analytical solutions to the scalar wave equation of motion. The resulting spectra refine the system’s behavior in the presence of large-scale rotation, which is crucial for describing quantum hydrodynamics in superfluids.
Sound travels through a medium at a certain speed. If the medium moves faster, the sound gets swept along by the flow — like a wood chip pulled into a whirlpool. In superfluid helium — a frictionless liquid — rapid rotation spawns vortex funnels. Inside them, an acoustic black hole forms: a region from which sound cannot return.
Researchers added uniform rotation and computed the resonant frequencies — the notes at which the vortex 'sings.' Using vibration analysis, they observed stable wave patterns within the curved space of the funnel.
These calculations help explain superfluid helium experiments and test Hawking’s hypothesis about black hole radiation without ever leaving Earth. Amazingly, the core of each vortex is a quantum thread as thin as an atom: a microscopic trap mimicking the cosmic abyss.
🎯 When cooled nearly to absolute zero, superfluid helium can circulate forever in a closed loop without slowing down — that’s the ideal frictionless liquid in action.
🎬 In *Interstellar*, the Gargantua black hole twists light; a lab vortex twists sound.